The canister is a container for storing the organic and inorganic metallic compounds used in a manufacturing process relating to semiconductors and electronic materials. Most of the organic and inorganic metallic compounds are specially designed expensive compounds of high purity, and most of such precursors are very sensitive to air or water, and so the canister is made of a metal providing sealing and resistance to chemicals.
The canister must be kept at a given temperature in order to preserve the organic and inorganic metallic compounds stored therein. To this end, a chiller is used for cooling the canister.
The chiller encloses the canister, circulating cooling water for cooling the canister. A chiller is disclosed in Registered Patent No. 10-0773474 entitled as “CHILLER SYSTEM FOR SEMICONDUCTOR MANUFACTURING EQUIPMENT”.
FIG. 1 is a cross-sectional view of a conventional chiller 10. As shown in the drawing, the chiller 10 includes a tray 11, and an inner casing 13 inserted in the tray 11 for receiving a canister 20. As indicated by an arrow, the cooling water a, supplied through an inlet tube 15 flows through aperture 13abetween the inner casing 13 and the canister 20, discharged through a discharge tube 17.
The inset shown in FIG. 1 is an enlarged view of the upper sealing structure of the conventional chiller sealing block 18, sealing cover 18a, sealing member 19, and engaging member 179.
In this case, the chiller 10 is designed that the cooling water discharged from the inner casing 13 is collected in the space (S1) between the tray 11 and the inner casing 13, and then discharged through the discharge tube 17. Here, the temperature of the cooling water is different from the atmospheric temperature of the outside, and therefore vapor is condensed on the outside wall of the tray 11 to produce dew (M) causing a problem.